Dual weapon system alignment mechanism



2,949,825 Patented Aug. 23, 1960 ice DUAL WEAPON SYSTEM ALIGNMENT NIECHANISM C Walton Musser, Beverly, Mass, and Francis W. Dietsch, Philadelphia, Pa., assignors to the United States of America as represented by the Secretary of the Army Filed May 7, 1958, Ser. No. 733,773

3 Claims. (CI. 89-41) (Granted under Title 3'5, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to an alignment mechanism for dual weapon systems such as those including a major weapon and a spotting rifle. It has for its principal object the provision of an improved alignment mechanism and method of operation whereby the probability of a first round hit by the major weapon is greatly increased.

With a major weapon of the low muzzle velocity type, it is essential that the range be accurately estimated if the probability of a first round hit is to be relatively high. When such an estimate is obtained by the firing of a spotting rifle, it is necessary that the trajectory of the projectile fired from the spotting rifle approximate as closely as possible the trajectory of the projectile fired from the major weapon. In accordance with the present invention this result is achieved by the provision of an improved alignment mechanism which is operable to effect a minimum of mismatch of trajectories of the projectiles fired from the two guns.

The invention will be better understood from the following description when considered in connection with the accompanying drawings and its scope is indicated by the appended claims.

Referring to the drawings:

Fig. 1 illustrates the physical relation between the major weapon and the spotting rifle,

' spotting rifle,

Fig. 5 shows a partial section taken on the line 5-5 of Fig. 4, and

Fig. 6 is an exploded view of the front support of the spotting rifle.

Fig. 1 shows a barrel 10 of a major weapon and a barrel 11 of a minor weapon, the barrel 11 being supported by brackets 12 and 13 which are fixed to the barrel 10. As is well known, the minor weapon fires tracer and spotter ammunition enabling the gunner to follow the trajectory of the bullet from gun location to the target and to determine the point of impact.

In order to utilize this information to the best advantage, means are required for minimizing mismatch of the trajectories of the projectiles fired by the minor and major weapons. Thus if the major caliber trajectory (curve A of Fig. 1A) is considered as fixed, the mismatch varies with the range, the ballistic coeflicient and launching velocity of the minor caliber projectile, and the angle between the axes of the two weapons. Assuming all these quantities, constant, muzzle velocity dispersion will affect the mismatch at all ranges. Curves B, Cand D of Fig. 1 indicate the extent of mismatch for a given ballistic coeflicient, optimum angle between the axes of the two weapons and different launching velocities of the minor caliber projectile. It will be noted that the curve C represents the best match. The achievement of this match is facilitated by the alignment mechanism about to be described. This mechanism is embodied in the front and rear brackets 12 and 13 the minor weapon is supported.

As indicated by Fig. 3, the rear bracket 12"has an opening 14 which is shrunk fitted onto the barrel 10 of the major weapon, and an opening 15 within which a rear portion of the minor weapon is mounted. The bracket 12 is also arranged to support certain fire control equipment which is omitted because it forms no part of the present invention. 7

Forming the rear mount of the minor weapon are a recoil pad 16, a pin 17, a gimbal spring 18 and a pressure ring 19. How these various parts are assembled to form a spherical bearing for supporting therear end of the barrel 11 is indicated more clearly in Fig. 2.

It will be noted that the barrel 11 is held'in place by the recoil pad 16 which fits into a groove in the barrel 11. The recoil pad 16 has a spherical surface on the back which rests in a spherical seat in the rear bracket 12. Holding the recoil pad in place are the gimbal spring 18 and the pressure ring 19. When the pressure ring 19 is tightened against the face of the bracket, the gimbal spring 18 has not reached solid height. Therefore angular adjustment can be made to the barrel 11 while still maintaining a spherical seat in the socket.

Rotation of the barrel 11 is prevented by the key 20 between the barrel 11 and the recoil pad 16 and the pin 17 which fits into a slot in the bracket 12 as indicated by Fig. 2.

Alignment of the barrel 11 is achieved by the parts of the mechanism which are located in the front bracket 13. As indicated by Fig. 6, these parts include cams 21 and 24, Belleville springs 22 and 23, a sleeve 25, a locking spring 26 and keying springs 27. It will be noted that the bracket 13 has at its upper end a horizontal slot 28 and a vertical slot 29. How these parts are as- .the cams.

sembled to permit elevation and transverse adjustment of the barrel 11 is indicated more clearly by Figs. 4 and 5.

From these figures, it is seen that the cam 24 rotates in the horizontal slot 28 for vertical adjustment of the barrel 11 and the cam 21 rotates in the vertical slot 29 for horizontal adjustment of this barrel. The Belleville springs 22 and 23 are fitted between the bracket 13 and the cams to seal out dust and provide friction within the mechanism. The key 26 has a protrusion which extends through an aperture 30 in the sleeve 25 into a keyway in the barrel 11. This fixes the sleeve to the barrel.

Upon the outer periphery of the sleeve 25 are eight longitudinal keyways adapted to cooperate with nine similar keyways on the inner peripheries of the cams. In each of the keyways on the sleeve is one of the leaf type springs 27. These springs have two protrusions (see Fig. 5) which fit into a radial groove in each of These protrusions prevent the mechanism from pulling apart. The cams are notched at their exposed edges to facilitate their rotation.

Rotation of either cam to attain proper alignment of the barrel 11 is effected by depressing the end of the leaf spring 27 (see Fig. 5) which engages the cam. Then the cam may be rotated until the next leaf spring enters the next keyway of the cam. With the number of keyways shown, this amount of rotation moves the barrel 11 approximately one-third of a mil.

The brackets 12 and 13 are designed to minimize the effect of the forces produced by the firing of the weapons. Thus the flanges of the brackets are cut away so that by which the fire control equipment is protected from the recoil shock of the minor weapon and the web of the brackets is cut away so that radial expansion of the major weapon upon firing does not transmit its force directly to the sighting equipment.

We claim:

1. In a combination with major and minor weapons, a rear bracket fixed to the barrel of said major weapon and arranged to support a rear portion of said minor weapon in a spherical bearing on said bracket, a front bracket fixed to the barrel of said major weapon and having an opening through which the barrel of said minor weapon extends, said opening having on its inner surface first and second slots which are perpendicular to one another and to the axis of said minor weapon barrel, a first eccentric cam rotatable in the first of said slots for traversing said minor weapon barrel and movable longitudinally of said first slot during elevation of said minor weapon, a second eccentric cam rotatable in said second slot for elevating said minor weapon barrel and movable longitudinally of said second slot when said minor weapon barrel is traversed, and means for locking said cams to said minor weapon barrel in diiferent angular positions.

2. In a combination with major and minor weapons, at rear bracket fixed to the barrel of said major weapon and arranged to support a rear portion of said minor Weapon in a spherical bearing on said bracket, a front bracket fixed to the barrel of said major weapon and having an opening through which the barrel of said minor weapon extends, said opening having on its inner surface first and second slots which are perpedicular to one another and to the axis of said minor weapon barrel, a first eccentric cam rotatable in the first of said slots for traversing said minor weapon barrel and movable longitudinally of said first slot during elevation of said minor weapon, a second eccentric cam rotatable in second slot for elevating said minor Weapon barrel and movable longitudinally of said second slot when said minor weapon barrel is traversed, said cams having on their inner surfaces a series of longitudinal slots, a sleeve keyed to said minor weapon barrel and having on its outer surface a series of longitudinal slots, and a locking spring in each slot of said sleeve whereby said cams may be locked in any one of a plurality of different angular positions.

3. In a combination with major and minor weapons, a rear bracket fixed to the barrel of said major weapon and arranged to support a rear portion of said minor weapon in a spherical bearing on said bracket, a front bracket fixed to the barrel of said major weapon and having an opening through which the barrel of said minor weapon extends, said opening having on its inner surface first and second slots which are perpendicular to one another and to the aXis of said minor weapon barrel, a first eccentric earn rotatable in the first of said slots for traversing said minor weapon barrel and movable longitudinally of said first slot during elevation of said minor weapon, a second eccentric cam rotatable in second slot for elevating said minor weapon barrel and movable longitudinally of said second slot when said minor weapon barrel is traversed.

References Cited in the file of this patent UNITED STATES PATENTS 1,239,287 Masterton Sept. 4, 1917 1,487,801 Pedersen Mar. 25, 1924 2,125,932 Lennon Aug. 9, 1938 2,311,186 Lobdell Feb. 16, 1943 2,641,860 Dial June 16, 1953 2,770,041 Boll Apr. 6, 1954 

